Due to technological advances and improvements in patient care the survival rate of the extremely low birth weight (ELBW) preterm infants has increased substantially, resulting in a significant increase in the number of patients with bronchopulmonary dysplasia (BPD). BPD has become a major public health problem with 7,000 to 10,000 new cases occurring each year. These preterm infants (500 to 1,500 g birth weight) remain in Neonatal Intensive Care Units (NICUs) for extended periods and often receive a variety of potentially toxic medications for their lung disease with no practical way of accurately determining the need for such treatment or monitoring its effectiveness. This is because currently, there is no non-invasive pulmonary diagnostic/monitoring device available for NICU use. We have developed a non-invasive pulmonary diagnostic device, Airflow Perturbation Device (APD) that can evaluate the respiratory resistance of patients non-invasively, rapidly, and effortlessly in less than one minute. The device is small, portable and can be produced at a very low cost. The APD has been considerably enhanced using the NIH NHLBI SBIR grant, now at the end of its Phase II term. We have validated the APD on over 2,000 individuals aged 2 to 88 years. Recently, using the APD, we have explored the possibility of evaluating respiratory resistance of preterm and full term infants at Georgetown University Hospital (using an IRB approved protocol). The results are encouraging and indicate that, with some device enhancement (more sensitive pressure and flow transducers, reduced dead space, etc), the APD can be adapted for infant population use. If successful, it will be the only device that can non-invasively diagnose/monitor the pulmonary function of preterm infants. This would fill a critical need in the NICU and outpatient clinic, allowing for improved care and more rational use of potentially toxic medications. The new enhanced device, the "Neonatal APD", will meet the stringent requirements for a device for use in newborns (high sensitivity, low dead space, used with a face mask effortlessly). The final product will be a reliable device that can diagnose/monitor infant pulmonary function quickly, inexpensively and without active patient cooperation. The work proposed consists of two parts, engineering and clinical. The engineering aspect of the work includes modification and enhancement of the existing APD with sufficient sensitivity to detect the small infant mouth pressure and flow reliably in 20 seconds, reducing dead space. In the clinical part we will evaluate respiratory resistance of 200 preterm and full term infants. The subjects will include normal infants, those with BPD and other respiratory disorders. We will study infants receiving bronchodilators, diuretics, caffeine, etc. to demonstrate the ability of the device to detect changes in airway resistance in response to these therapies. This application is prepared in response to the request for application "RFA-HD-09-017;Safe and Effective Instruments and Devices for use in the Neonatal Intensive Care Units (SBIR [R43])". PUBLIC HEALTH RELEVANCE: There is a high incidence of bronchopulmonary dysplasia (BPD) in extremely low birth weight infants that has become a major public health problem with 7,000 to 10,000 new cases occurring each year. Currently there is no non-invasive device to diagnose/monitor these infants. We have developed such a device (APD) that works perfectly for children and adults. We are proposing to enhance the APD for use in infant population that will be non-invasive, sensitive, reliable and inexpensive. The new device, Neonatal APD will be a useful tool in Neonatal Intensive Care Units.